Remove note that claims pthread_set_name_np is for debugging only.
Remove note that claims pthread_set_name_np is for debugging only.

As Garrett points out,
  It is no more a debugging interface than setproctitle(3), and has not
  been since the name started getting stuffed into the kernel.  This
  statement may have made sense when the name was only visible in thread
  state dumps and the debugger.
PR:		threads/158815
Submitted by:	wollman@

jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase